It is difficult to see why you would do a multiplication using subtraction but one possible answer is: 8 * 604 = (10-1-1)*604 = 10*604 - 1*604 - 1*604 = 6040 - 604 - 604 = 4832
604
604
The positive integer factors of 604 are: 1, 2, 4, 151, 302, 604
778
55 x 604 = 33,220
126 x 604 = 76104
604
604
151
604
302 times 2 gives you 604.